High pressure alkylation reaction



Patented Aug. 10, 1943 4 2,326,587 HIGH PRESSURE ALKYLATION REACTION HansG. Vesterdal, Elizabeth, N. 3., assignor to Standard Oil Development Company, a corporation of Delaware No Drawing. Original application October 5,

1940, Serial No. 359,895. Divided and this application November 8, 1941, Serial No. 418,321

11B filaims. (Cl. 260633.4)

This application is a division of United States application Serial No. 359,895 filed October 5, 1940.

The present invention relates to the alkylation and/or polymerization reactions in which isoparafins are condensed with olefins and/or olefins are condensed with either similar or dissimilar olefin molecules to yield normally liquid, branched chain, saturated and/ or unsaturated hydrocarbons which find uses as blending agents and have direct application to utilization in the production of motor fuels.

It isknown to condense isoparafins with-olefins and to condense olefins with similar or .dissimilar olefin molecules to produce alkylation reaction products and/or polymerization products. This has been done thermally, that is, by the application of heat alone, and it has also been accomplished by resorting to the use of certain catalysts under quite varying reaction conditions. Among the catalysts employed for effectingcondensation of olefins, either with themselves or with isoparaffins, may be mentioned concentrated sulfuric acid, aluminum chlorid with or without the use of hydrogen halide, and various other Friedel-Craits type catalysts, boron fluoridewater mixtures and their resulting chemical compounds, phosphoric acid either alone or deposited on carriers such as kieselguhr and the like, and various other similar compounds.

The process of the present invention is primarily concerned with the production of normally being carried out simultaneously under reaction conditions conductive to the production of normally liquid hydrocarbon condensation products,

the said reactions being" catalyzed by the presence of one or more substances taken from the group consisting of oxides and sulfides of metals of group ,5 of the periodic system. In carrying out this process it is necessary, however, in order to secure the desired results to have present in the reaction zone during the reaction small amounts of a substance having the formula HQX, wher'ein X is either oxygen or sulfur. In other words, the reaction is carried out in the presence of water or hydrogen sulfide." However, it may also b carried out in the presence of a mixture of these two substances. Fundamentally, the reaction is a vapor phase process. However, under certain restricted specific reaction conditions where a proper choice of reactants has been made it may be possible and at timesdesirable to carry out the reaction in th liquid phase. Ordinarily, however, vapor phase reaction is preferred.

The various catalysts which are contemplated may be further defined as including the oxides liquid, branched chain, substantially completely saturated hydrocarbons boiling within the motor fuel boiling range, but is of necessity concerned with the production of polymers of olefinssince the reaction taking place according to the process of the present invention is not one of alklation to the exclusion of one of polymerization. In other words, while it is possible to produce substantial quantities of polymers in the reaction mixture, nevertheless it is an object of the present invention to so manipulate the reaction conditions, catalyst, reactants, etc., to obtain as high yields as possible of the desired alkylates, The product as prepared according to the present invention therefore predominates in saturated, branched chain; normally liquid hydrocarbons.

The process of the present invention maybe in general described as efiecting a condensation between at least one isoparaflin and at least one olefin,,'preferably a mono-olefin, and/or a condensation between an olefin, preferably a monoolefini and another olefin either of similar or dissimilar configuration, these two types of reaction and sulfides of vanadium, columbium and tantalum. It is unnecessary, and in fact at times undesirable, to employ any one o'ithese specific compounds as the catalyst. It is oftentimes desir--' able to employ a mixture of one of these catalysts with other metal oxides or sulfides of groups 6 and 7 of the periodic system, vanadium and chromium oxides, vanadium and molybdenum oxides, or a three-component catalyst such as, for example, vanadium, chromium and molybdenum oxides may be employed. It is within the scope of the present invention to employ mixed catalysts of oxides and sulfides, for example,

- chromium oxide admixed with vanadium sulfide.

pounds. In the preferred embodiment of the invention the oxide catalysts are preferred, not only because of their increased activity with respect to alkylation but also because of their greater ease of regeneration. The regeneration process will be described-hereinafter. Furthermore, there is one other advantage to the use or the oxide catalysts, particularly when used in connection with water as the' promoter, and that is with respect to the recovery of the desired final products. In cases where sulfides and hydrogen sulfide are employed in the reaction, it is often-- times-necessary to resort to an alkali wash in order to remove from th final product dissolved sulfur compounds, whereas in connection with the use of oxide catalyst with, a water promoter it is unnecessary to subject the final desired product to such purification treatment.

Although the above described catalysts may be employed alone in the process of the invention, it

is desirable particularly in commercial operations and from the economical standpoint to employ the catalyst in conjunction with a carrier. The types of carrier employed may be quite varied in nature and although no determination has been made it is felt that in some instances the carriers are not inert in the reaction and in some manner contribute to the ultimate final yield of the desired products. Carriers may beeither of the porous or nonporous type, although since the reaction embodying the invention is thought to be essentially a surface reaction it is preferred to employ the porous carriers. These carriers are of the type action conditions, the amount of catalytic component of the catalyst mass may vary considerably. Thus, when carrying out the reaction under drastic reaction conditions a lesser amount of the catalytic component of the catalyst mass is ordinarily required than is the case where the redetermined size.

such as clays, either natural or acid activated, the

els such as, for example, alumina gel or silica gel, bauxite, fullers earth, bentonite, kieselguhr, pumice, celite, montmorillonite, marsil, tonsil,

, Super Flltrol, activated floridin, activated charcoal or activated carbon; and various other types of carriers such as piecesof porcelain or chemiby precipitating the aforementioned metal salts on the hydro gels and heating in the same manner as the oxides are produced. This catalyst mass may be then treatedwith hydrogen sulfide, ammoniumsulfide. or some" equivalent sulfide compound in order to convert. the metal oxides to their corresponding sulfides. Mixtures of two or more of the p rous carriers may be employed as, for example, a mixed alumina-silica gel or' an activated carbon admixedwith an aluminavor.

silica gel. In connecidon'withthe deposition of the metal oxides or sulfides on the non-porous type carriers. .it is sometimes advantageous to employ a binder. Generally, however, a wetting of the non-porous carrier followedby drying or thermal treating to convert to the oxide is sufficient to leave a coating on the carrier which is adequate for use in the-reaction. The amount oi oxides and/or sulfides of the metals of the fifth group of the periodic system deposited may vary considerably with respect to. the carriers employed. In generah however,-the ultimate. percentage of oxide and/or sulfideof the metals im presnated in or deposited on these carriers varies" betweenabout 1% and about 10% or evenas high as preferably between 7%- and 20% by weight of the amoimt of carrier employed.

Runs have been made employing catalysts wherein the metal oxides or sulfides constitute as high 8s 5: of the total weight of the catalyst. The optimum percentages of metal oxides or sulfides deposited on the various carriers depends to some extent upon the available surface area of the carrier employed. Also, depending upon the re-.

action is carried out under milder reaction conditions, in which case a larger portion of the catalyst mass is preferably the active catalytic component.

The catalyst may be prepared in any desired form such as, for example, pills, pellets, briquettes or powder, or some other finely divided or com minuted form. It is likewise possible and at time preferred toextrude the catalyst composition,

particularly where the gels are employed, in the form of the hydro gels through orifices of pre- The extruded catalyst is then heated to drive oil the water and to decompose the metal salts to the corresponding metal oxides or sulfides.

The specific oxides and sulfides employed in the process of the invention may vary in form depending upon the degree of oxidation of the particular metal. In general, it is proposed to employ those oxides and sulfides of metals which constitute at least theoretically the acid anhydrides of those metals employed. Thus, for example, CrzOa' is employed since it is considered to be the acid anhydride of chromous acid. C103 is employed since it is considered to be the acid anhydride of chromic acid. Similarly, M003 is employed as being the counterpart of molybdic acid. This analogy likewise applies to the sulfides since, for example, Moss is considered the acid anhydride of thiomolybdic acid and CH8: is considered the acid anhydride of thiochromous acid. Various other oxides and sulfides of chromium may be employed. Thus, for example, CrOz, CrS and C13S4 maybe employed. In the case of vanadium oxides and sulfides, the compounds customarily employed are V2S5, V2S3, V282, V205, V204, V203 and V202. The manganese compounds include MnSz, MnS, MnzOs, M12201, MnOz, etc. It should be distinctly understood, however, that although no definite information is to be had at the present time, these various oxides. and sulfides when deposited on the carriers and employed in the reaction under the hereinafter specified reaction conditions are very probably altered in their'chemical structure by reason of the reaction conditions to the more stable oxides and sulfides. A catalyst of the type employed may be prepared by co-precipitating the hydroxides of alu- 'minum and chromium wherein the molar ratio of aluminum to chromiumis ultimately to be about 2:1 with ammonia from a solution of the aluminum and chromium nitrates. The resultant gel is washed and dried, molded or pressed into the desired shape, for example, pills, and then heated to about 800 F. for a length of time sufiicient to substantially completely dehydrate the same. To prepare a molybdenum oxide catalyst, the hydroxide of aluminum was impregnated with an aqueous solution of ammonium molybdate sufilcientso that the catalyst will contain about 9% V of-molybdic oxide inthe final product. The resultant mass was washed andheated for about 30 minutes at 1200 F. The powder obtained was then pressed or briquetted into the desired pellet form for use in the reaction. Another catalyst which has found use in the present reaction was prepared by admixing aluminum hydroxide with silica hydro gel and adding thereto a sufiicient amount of an aqueous solution of ammonium vanadate and homogenizing the same. The resultant mass was then washed, freed of excess water, 'pilled and then heated to about 800 F. for about 3 hours. This composition contained about 1.7% of vanadium pentoxide. The weight ratio of silica to alumina wasmaintained at about 1.7 :1.

The reaction ma be carried out using a variety of reactants. It is necessary that at least one 01' the reactants be an isoparaffln, that is, a par aflinic hydrocarbon containing at least one tertiary carbon atom per molecule. Such compounds are isobutane, isopentane and higher homologues are suitable as one of the reactants in the process. Mixtures of two or more of the isoparairlns may likewise be employed, particularly where safety fuels and aviation naphthas.

and the like are the desired final products. The presence of normal parafilns in admixture with isoparaffins is in no wisedetrimental to the activity of the isoparaflins. In fact, there is some indication that a portion at least of the paraflinic constituents of the feed stock may to some extent become dehydrogenated during the reaction to form the corresponding olefinic compounds.

- and/or dehydrogenated prove a distinct benefit by their presence in the reaction feed stock.

Theolefinic reactants may be selected from a number of the common olefins present in refinery gases and to be found elsewhere as well. For example, ethylene, propylene, normal butylenes, isobutylene, the isomeric pentenes, and similar higher monoolefinic hydrocarbons of either a straight chain or branched chain character, may be employed. Mixtures of two or more of these olefins may be employed as the oleflnic components of the feed stock. It is generally preferred to employ normally gaseous olefins as the reactants but this is chiefly because of economic factors. Normally liquid 'monooleflns, however, are equall desirable. Such oleflns are polymers,

copolymers, interpolymers, etc., of the above- ,mentioned monooleflns, these being, for example, 'diisobutylene, triisobutylene, the polymers resulting from the condensation of normal butylenes with isobutylene, of butadiene with butylenes, and the like.

Suitable sources of the various olefins and isoparam'ns are to be found in the gases coming from the thermal and/or catalytic cracking units of an oil refinery, from field butanes which have been subjected to prior isomerization and/or partial dehydrogenation treatments, from refinery stabilizer bottoms, from stabilizer overhead gases,

in some instances. The process may be carried out either as a batch, continuous or semi-continuous type of op- 5 eration. Economic considerations make it pref: erable to carry the process out in a continuous manner, especially where the process is operated on a commercial scale. should be intimately contacted with the catalyst since the reaction is apparently a contact type and higher yields of the desired product are obtained by a vigorous and intimate mixing or agitation of the-reactants in the presence of and be employed to advantage in carrying out the 7 present process.

The temperature under which the reaction is maintained may vary considerably. The reaction is carried out under temperatures ranging 80 between about 375 F. and about 950 F., preferably between about 575" F. and about 800 F. It isrealized of course that with each particular type of catalyst employed the optimum temperature varies considerably but in general the above temperature ranges are adequate for carrying out the reaction to give the desired motor fuel products.

' Theprocess is 'carried out under fairly high superatmospheric pressures. Pressures ranging 40 between about 500 and about 16,000 pounds per square inch, preferably between aboutql500 and about 14,000 pounds per square inch, are employed. The time of contact of the reactants with the catalyst under the temperature and pressure conditions above mentioned may vary considerably depending upon the temperature,

pressure and nature of the reactants employed. In general, the time of contact lies between about 1 and about 60 minutes, preferably between about 10 and about 30 minutes. Reasonable care should be exercised in correlating the abovedeflned reaction conditions together with the type of feed stock employed soas to avoid substantial cracking or carbonization of the hydrocarbons .55

fed to the reaction zone. Obviously,a temperature as high as 950 F. with a pressure of around 500 pounds per square inch and a time of contact of around minutes would'quite extensively carbonize and crack a feed stock containing Ca and C7 isoparaflihs in conjunction with C8 or C1: monoolefins. Likewise, the conditions should be sufllciently drastic to effect a substantial condensation of the olefinic components of the feed I nents of that feed stock. In other words, anextremely mild condition when employing diisobutylene with Ca and C7 isoparaffins; that is, a contact time of around 1 minute when using a pressure of around 500 pounds per square inch and a temperature of around 375 F. would obviously not be sufiicient to produce the desired result. Suflice it to say that the optimum reaction conditions for any particular feed stock to give out attendant sacrifice in quality of the product The reaction mixture the desired final products are best determined for any particular catalyst employed by one or two trial runs at varied temperatures, pressures and times of contact within the ranges heretofore outlined and in accordance with the principles of the invention as heretofore stated.

The amount of hydrogen sulfide and/or water added to the reactants or conducted directly into the reaction zone varies to a certain extent depending upon the amount of active catalyst present in the catalyst composition. In general, the amount of promoter added to the reaction or present in the reaction zone atanyonetime should be between about 0.5% and about 20% by weight of the catalyst mass, preferably between about 5% and about 15% by weight. As will be understood from the hereinafter described runs under the particular reaction conditions therein outlined, about by weight of water was found activity becomes somewhat impaired; The addition of elemental oxygen or elemental sulfur, depending upon whether the catalyst employed is an oxide or a sulfide, will to some extent reactivate the catalyst. The inactivity of the catalyst after prolonged usagehas been thought to 'be due largely to an accumulation or buildin up and clogging of the pores of the catalyst or. covering of the catalyst surface with carbonaceous deposits. The introduction of oxygen or sulfur, particularly where the carbonaceous deposits are of a soft or gummy consistency, will in some cases purge the mass of these deposits,

The regeneration or reactivation of the sulfide catalysts may require a somewhat different type of treatment. The above-described process for regeneration of the oxide catalysts may be resorted to and the resultant reactivated catalyst mass which finds the metal in combination with oxygen rather than sulfur is then dissolved in and although not completely reactivatin'g the mass, will substantially revivify the same and fit it for further usage in the reaction. In order to completely reactivate the catalyst once its catalytic activity has become substantially impaired, the catalyst is withdrawn from the reaction and, in the case of the oxide catalysts, the original activity may be restored by the introduction of air or oxygen either diluted with'inert gases such as, for example, ,nitrogen'or carbon dioxideor steam, at temperatures of between about 800 F. and about 1300 1?. for a sumcient length of time to enable the rapid oxidation of the carbonaceous material to substantially completely remove the same from the pores and from the surface of the catalyst mass. Thisintroduction of free oxygen-containingmaterials should be controlled so that the regeneration follows a. fairly even course andavoids the burning of! of ammonium lrvdro sulfide and treated with hydrogen sulfide to form the ammonium thio metallate.

Acidification of this mass with sulfuric acid precipitates the metal sulfide which is then heated in the presence of a reducing gas such as, for

example, free hydrogen, at between about 500 and about 800 F. to form the more stable and more active metal sulfide catalyst. This material may then be formed into pills and the like or it may be directly reused in the process of the invention.

As illustrative of the method of carrying'out the process of the invention, but without unduly restricting the invention to the scope specifically disclosed, thefollowing example isv submitted a Example To a bomb maintained at a'temperature of about 700 F. there was added about grams of catalyst. This catalyst was prepared by homogenizing a silica hydro gel with'aluminum, oxide and adding. thereto 'sumcien 1f ammonium va-..

nadate so that upon subsequent treatment the catalyst mass would contain about 1.69% ,by weight of V204. The homogenized mixture was dried, pilled and then heated to about 800 F.

for about 3 hours.. The weight ratio of silica to alumina was about 1.7 to 1. To this catalyst there was added about 11% by weight of water and admixed with this catalyst mass was 365 grams of isobutane. ,To this reaction mixture there was slowly added over a periodof about-19 minutes, while maintaining the reaction mass at a temperature of between about 700 F. and about 720 F., about 115.8 grams of propylene. The pressure rose from an initial pressure of about 7,000 pounds 'per square inch to around 14,000 pounds per square inch. The bomb was shaken and the reaction mixture was maintained under these reaction conditions for an additional 30 minutes, at the end of which time the temperature was around 720 F. and the pressure was about 13,000 pounds per square inch. A normally liquid product was recovered in an amount of about 100.7 grams which amounted to about 87.2% of the propylene charged or about 115.4% of the propylene reacted. Of this product about 55.8% constituted theCs-Cs fraction. It had a bromine number of 54, while the residue had a. bromine number of about 19.

The nature and objects of the invention hav-' ing been thus fully described and illustrated,

what is claimed as new and useful and desired to a be secured by Letters Patent is:

the carbonaceous mass at erratic rates since the 4 heat of combustion is difllcult to remove where the oxidation processjbecomes too rapid. After the carbonaceous material has been burned off the catalyst is then ready for reuse in there; action. This method of regeneration is simply illustrative of any number of conventional accepted methods for regenerating catalysts'emq, ployed in hydrocarbon reactions and the P 6 1; of the invention is by no means limited or restricted to the described regenerative fmethod.

Any suitable regenerative method maybe-e ill-07 .1. A process of reacting isoparafilns with olefins to produ e saturated, normally 'liquid.

branched chain hydrocarbons which comprises carrying out said reaction at temperatures ,be-

tween about 375' 1". andabout 950 F. under superatmosphericpressures in contact with a.

contact of the reactants with the catalyst under the reaction conditions is correlated to avoid'substantial carbonization and cracking. 1

3. Aprocess which comprises reacting an isoparaflin with a monoolefin at a temperature between about 375 F. and about 950 F. under paraflin is present in molar excess over the olefin and the'catalyst is a vanadium oxide on a silica-alumina gel.

5. A process as in claim 3 wherein the catalyst is a vanadium oxide.

6; A process as in claim 3 wherein the catalyst is a vanadium sulfide.

'7. A process as in claim 3 wherein the HQ! compound is added to the feed and-the process is carried out continuously. y

8. A process which comprises condensing isobutane with at least one normally gaseous olefin at a temperature between about 550 F. and about 900 F. under a superatmospheric'pressure be tween about 1000 and about 14,000 pounds per square inch for between about. 10 and about minutes in contact with at least one member of the group consisting of oxides and sulfides of metals of group 5 of the periodic system and in contact with between about 5% and about 15% by weight of the catalyst mass of a member of the group consisting of hydrogen sulfide and water, correlating the reaction conditions to avoid substantial cracking'and carbonization and recovering a normally liquid product.

9. A process as in claim 8 wherein the catalyst is supported on and employed in conjunction with a carrier.

10. A process which comprises condensing isobutane with propylene, the isobutanezpropylene molar ratio being-maintained at at least 3:1 at a temperature between about 700 F. and about 720 F. under a pressure between about 7,000 and about 14,800 pounds per square inch, the propylene being added gradually over a period or about 19 minutes with an additional 30minutes reaction time in contact with vanadium pentoxide impreganted in a pilled double silica aiumina gel, saidcatalyst having added thereto about 11% of its weight of water, and recovering substantially saturated, branched chain, normally liquid hydrocarbons from the reacted mixture.

HAN/S: a. VESTERDAL. 

